Describe what a Host Specific Parasite is.
a parasite that develops completely in only one type of host, e.g., dog
Describe the term Broad Host Spectrum
(Non-Host Specific) Parasite - a parasite that can develop in different types of hosts, e.g., cattle, sheep, horses.
Describe the term Definitive or Final Host
a host in which the parasite develops to its mature stage.
Describe the term Intermediate Host (IH)
a host in which the parasite develops to that stage which is infective for the DH. The IH, with the infective stage generally encysted in some tissue, is usually part of the food chain of the DH. When the DH ingests the IH, the infective stage, enters the DH. For some helminths, the IH is a biting arthropod, and transmits the infective stage via its mouth parts when biting the host.
Describe the term Paratenic Host (PH)
a host in which there is no development of a helminth, and in some instances protozoa, but one that transmits the infective stage of the parasite, and allows for its wider dissemination. The PH, with the infective stage of the parasite encysted in some tissue, usually is part of the food chain of other PHs or DHs. A PH is sometimes referred to as a transport host.
Describe the term Biological Vector
a host, usually a biting arthropod, in which a protozoan parasite develops through either asexual or sexual multiplication, and transmits the parasite via its mouth parts on subsequent biting of a DH, or in its feces deposited on the DH as it is feeding.
Describe the term infection
endoparasites such as helminths and protozoa infect the host internally
Describe the term infestation
when ectoparasites such as acari and insects attach to or occupy the host
The predilection site is:
preferred site in or on the host, which is characteristic for a parasite species
The Aberrant site is:
the site in or on a host which is not a normal location for a parasite.
List the general characteristics of insects.
- 3 pairs of legs
- A body divided into head, distinct thorax and abdomen
- A single pair of antennae
Arachnids have _______ rather than antennae
The two families of ticks are ________ and _________
The two familes of ticks are Ixodidae (hard ticks) and Argasidae (soft ticks)
Which family of ticks are known for having a rigid chitinous scutum that covers the entire dorsal surface of the adult male?
Ixodidae (hard ticks)
True or False: Helminths include nematodes and cestodes, but not trematodes.
Helminths (worms) include nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes)
True or False: Nematodes are primarily identified by their segmented, flat appearance
Nematodes; or roundworms, are usually unsegmented, elongated, & cylindrical in shape.
List the general characteristics of nematodes
- May be free-living or parasitic
- usually unsegmented, elongated, and cylindrical in shape
- An alimentary canal is present
- Sexes are usually separate and the females are generally longer than the males
That roundworm got a free pair of unsellable elf cysts for all camels
"what the fuck is Chris smoking?"
Why are female nematodes typically longer than males?
Females hold the eggs
With regard to nematodes, the L4, L5/immature adult, and adult always occur in the __________ host
When no intermediate host is involved, the life cycle is considered to be ________.
When one or more intermediate hosts are involved, the life cycle is considered to be ________.
True or false: The alimentary canal of a cestode can be seen at 10x under a microscope.
The alimentary canal on a cestode (or tapeworm) can't be seen under any magnification... because tapeworms don't have an alimentary canal.
The body of a cestode is also known as the ________
The strobila includes the head, neck, and proglottids
Cestode life cycles are ________.
(direct or indirect)
List the general characteristics of trematodes
Trematodes (or flukes) are:
- dorso-ventrally flattened (leaf-like)
- Oral & ventral suckers for attachment
- Usually genitally independent; hermaphroditic
Trematodes belong to the phylum ________ and the class ________
Trematodes belong to the phylum Platyhelminthes and the class Trematoda
Are trematode life cycles direct or indirect?
At least 1 intermediate host is required to complete the life cycle.
Larval stages develop & multiply asexually in a molluscan intermediate host.
If we're discussing a parasite whose larval stages develop and multiply asexually in a molluscan intermediate host, you know right away that that parasite belongs to which taxonomic class?
How do humans become infected with Toxocara canis?
Ingestion of infective egg containing L2
How do humans become infected with Ancylostoma braziliense?
Percutaneously by L3